<template>
  <div>
    <el-tree ref="tree" :data="treeData" node-key="label" :props="defaultProps" empty-text="还没有树结构哦"
      :show-checkbox="false" :highlight-current="true" :current-node-key="current_node_key" @node-click="nodeClickFn"
      :default-expanded-keys="expandedKeys"></el-tree>

  </div>
</template>

<script>
export default {
  data() {
    return {
      treeData1: [],
      current_node_key: '',
      expandedKeys: [],
      treeData: [{
        label: '一级 1',
        children: [{
          label: '二级 1-1',
          children: [{
            label: '三级 1-1-1'
          }]
        }]
      }, {
        label: '一级 2',
        children: [{
          label: '二级 2-1',
          children: [{
            label: '三级 2-1-1'
          }]
        }, {
          label: '二级 2-2',
          children: [{
            label: '三级 2-2-1'
          }]
        }]
      }, {
        label: '一级 3',
        children: [{
          label: '二级 3-1',
          children: [{
            label: '三级 3-1-1'
          }]
        }, {
          label: '二级 3-2',
          children: [{
            label: '三级 3-2-1'
          }]
        }]
      }],
      defaultProps: {
        children: 'children',
        label: 'label'
      }
    }
  },
  methods: {
    nodeClickFn(value, node, nodeEle) {
    },
  },
  mounted() {
    this.expandedKeys.push('二级 3-2')
    this.$nextTick(() => {
      this.$refs.tree.setCurrentKey('二级 3-2')
    })
  },
};
</script>

<style></style>